Two young Canadian boys were killed in their sleep by an African rock python on Monday, after the huge snake apparently escaped from its enclosure and slipped into an upstairs apartment.

Aged 5 and 7, the two boys have been identified as Noah and Connor Barthe, who were sleeping the night at an apartment above the Reptile Ocean pet store in Campbellton, New Brunswick. They were found dead early Monday morning.

Royal Canadian Mounted Police Const. Julie Rogers-Marsh told The Star that the reptile appears to have made its way into a ventilation shaft and then into the living room where the boys were sleeping, in an apartment owned by shop owner Jean-Claude Savoie, a friend of their father.

"My body is in shock. I don't know what to think," said Savoie to Global News, describing the children as like his own. "I thought they were sleeping until I [saw] the hole in the ceiling. I turned the lights on and I [saw] this horrific scene," he added.

"The preliminary investigation has determined that the two boys were strangled by the snake," said Rogers-Marsh. Autopsies were due to be conducted Tuesday.

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An investigation has been launched into the incident to determine whether anyone bears criminal responsibility for the boys' deaths, reports Sky News. No charges have been filed so far.

Police said in a statement that they had captured the snake.

Snake experts remain baffled by the behavior of the creature, as it is out of character for the species, according to CBC News.

"It's strange, I'm just trying to piece it together," said Lee Parker, the facilities manager at Ontario reptile zoo Reptilia, to CBC. "They don't go on killing sprees... it doesn't make sense to me."

The African rock python is the largest snake species found in Africa and although it is non-venomous, is described as possessing a "particularly aggressive reputation" by a BBC source.

Pythons hunt by constriction, as they choke the air out of their intended prey, sometimes taking game as large as warthogs and crocodiles in their native habitat.